The present invention relates to a roller added to a reverse image printer that will provide reliable separation and removal of a printed laminated layer of material from a backing web or film after the printed layer has been laminated onto an identification card in particular.
U.S. Pat. No. 5,277,501 illustrates a method of transferring hot melt ink to a recording medium. The present invention provides a positive removal of the printed layer, called a printed transfer layer, from the backing film after the printed transfer layer has been laminated onto a substrate, specifically an identification card. In the prior art, the problems of having xe2x80x9cflashxe2x80x9d or flakes of the printed transfer layer separate from the web and the cards are present. In other words, there would not be a smooth and positive peel-off of all of the printed transfer layer that should be transferred from the web or film to the card. Flakes tend to come loose from the card in use, particularly along the edges and sides.
In the prior art, metal guide frames have been used with rounded noses for guiding the web or film after lamination of the printed transfer layer to the card to aid in separating the printed transfer layer from the backing web. The lamination process uses hot rollers that melt the ink at the interface of the transfer layer with the card to cause the transfer layer to adhere to the card surface. It has been recognized that residual heat stored in the guides for the web after lamination is not desirable. The conventional peel-off bars have had material removed from them in order to reduce heat storage. However, the problems with flakes or flash that separate from the printed lamination material forming the transfer layer remain.
The present invention relates to a reverse image printer, wherein a film or web carries a printable transfer layer that is printed with a reverse image and then laminated to a substrate, such as an identification card. The transfer layer may be a transparent layer of material on which images are printed using a printhead and separate ribbon, or the layer can be an ink layer on a transparent film or sheet on which images are created.
Apparatus for insuring reliable removal of the transfer or laminate layer from the web or film that carries the transfer or laminate layer after the layer has been through the lamination station is provided.
In an intermediate transfer printing process, a backing film or web carrying a transparent transfer layer is passed through a printer where a reverse image is printed. The transfer layer is then laminated to an aligned and indexed substrate, such as an identification card. The printed transfer layer comprising the laminate that is to applied to a substrate or card is pressed against the card and is heated with lamination rollers to cause the printed transfer layer to adhere to the surface of the card. The transfer layer or laminate has to then be separated from the backing film or web that carries it, while the transfer layer remains as a smooth, uninterrupted layer on the card. The backing web, the transfer layer and the card are moved in unison from the heated lamination rollers and across a separation or peel-off roller where the backing web or film is being separated from the transfer film by directing the backing web toward a web take-up roller at a separation angle relative to the plane of the card and the transfer film, now laminated to the card. The peel-off roller has a relatively small radius, and is positioned so that as the backing web material moves toward the take-up roll for the web material, and the card continues on its path or plane of movement, the angle formed between the plane of the path of movement of the laminated card and the plane of the backing web material as it moves toward the take-up roll is selected to guide the web away from the transfer layer and card without an abrupt change of direction. The tendency of the backing web and transfer layer, to stick together is reduced and the transfer layer stays laminated to the card. The problems with flaking, where flakes of the transfer layer break off or delaminate from the card, particularly along the transfer layer and card edges are reduced.
It is desirable to cool the transfer layer after lamination to insure it sticks to the card. Thus adding heat stored in the peel-off roller is undesirable. The present peel-off roller is mounted on a heat insulating mounting, and it does not have a large mass acting as a heat sink. Further, the mounting is made so cooling air can circulate over the peel-off roller and the backing web.